Unfortunately, they aren't carried on Platte or the Independence site. I've only heard MERS traffic on the KCMO site.MARRS is P25.
I would suggest trying the Platte County, MO simulcast portion of MARRS. One of the towers is in Leavenworth according to the license.
Right now, the control channel is running on 858.43750. The database does not currently show it as a control channel, so if you are using the site to load up you scanner, you will probably need to add this frequency to your list of system control channels.
My decode of the Platte county is poor, so I can't guarantee that the MERS talk group 33017 is carried on this system, but it most likely is.